Gas pain in the flank area: what to know

The flank is the area between the ribs and the hip, on either side of the back. Gas or constipation can cause shifting pressure, bloating and relief after passing wind or stool. Kidney stones may cause intense, cramping pain that travels toward the groin, while a kidney infection can cause flank pain with fever, chills, nausea or feeling unwell. A urinary tract infection may cause burning urination, urgency or cloudy urine. Muscle strain is another possibility, particularly when movement or pressing the area changes the pain.

Notice whether the discomfort changes after passing wind, using the toilet, changing position or eating. Drink fluids normally unless a clinician has advised fluid restriction, and choose gentle movement if it feels comfortable. Avoid taking anti-inflammatory painkillers without advice if you have kidney disease, stomach problems or dehydration. Do not rely on gas remedies when pain is fixed, severe or accompanied by urinary changes. A clinician can examine your abdomen and back and decide whether urine testing or other assessment is needed.

Seek urgent medical care for sudden severe flank pain, fever with flank pain, repeated vomiting, blood in the urine, inability to urinate, faintness or marked weakness. Arrange prompt review for pain that persists, returns, worsens, or comes with burning urination or urinary urgency. Pregnancy, a single functioning kidney, known kidney disease or recent urinary procedures lower the threshold for contacting a clinician.

Could this be bowel gas, a muscle problem, a kidney stone or an infection? Should my urine be tested? Which pain medicines are safe with my health conditions and current medicines? What changes would mean I need urgent care?